U.S. patent number 4,798,740 [Application Number 07/030,364] was granted by the patent office on 1989-01-17 for polymerizable film and pattern forming method by use thereof.
This patent grant is currently assigned to Canon Kabushiki Kaisha. Invention is credited to Ken Eguchi, Haruki Kawada, Toshiaki Kimura, Hiroshi Matsuda, Toshihiko Miyazaki, Kenji Saitoh, Kunihiro Sakai, Kiyoshi Takimoto, Yoshinori Tomida.
United States Patent |
4,798,740 |
Tomida , et al. |
January 17, 1989 |
**Please see images for:
( Certificate of Correction ) ** |
Polymerizable film and pattern forming method by use thereof
Abstract
A polymerizable film is provided which comprises a transition
metal and a polymerizable compound, and having a solubility in a
solvent which changes through a maximum and a minimum repeatedly
with an increase in energy imparted for polymerization. The
polymerized film may comprise a polymerizable compound represented
by the formula: wherein R and R.sub.1 are hydrophobic sites, X is a
hydrophilic site, and n is 0 or 1. This polymerizable film is
useful as recording materials and resist materials.
Inventors: |
Tomida; Yoshinori (Atsugi,
JP), Sakai; Kunihiro (Yamato, JP), Matsuda;
Hiroshi (Atsugi, JP), Kawada; Haruki (Atsugi,
JP), Eguchi; Ken (Atsugi, JP), Kimura;
Toshiaki (Sagamihara, JP), Takimoto; Kiyoshi
(Atsugi, JP), Saitoh; Kenji (Yokohama, JP),
Miyazaki; Toshihiko (Atsugi, JP) |
Assignee: |
Canon Kabushiki Kaisha (Tokyo,
JP)
|
Family
ID: |
27301126 |
Appl.
No.: |
07/030,364 |
Filed: |
March 26, 1987 |
Foreign Application Priority Data
|
|
|
|
|
Mar 31, 1986 [JP] |
|
|
61-73111 |
Mar 31, 1986 [JP] |
|
|
61-73112 |
Apr 3, 1986 [JP] |
|
|
61-77023 |
|
Current U.S.
Class: |
427/493; 264/104;
264/298; 264/485; 264/488; 427/504; 427/510; 430/270.1;
430/281.1 |
Current CPC
Class: |
G03F
7/025 (20130101); G03F 7/029 (20130101) |
Current International
Class: |
G03F
7/029 (20060101); G03F 7/025 (20060101); B05D
003/06 (); G03C 001/76 (); G03C 001/71 () |
Field of
Search: |
;427/43.1,54.1
;430/270,281 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Morgenstern; Norman
Assistant Examiner: Padgett; Marianne L.
Attorney, Agent or Firm: Fitzpatrick, Cella, Harper &
Scinto
Claims
What we claim is:
1. A polymerizable film, comprising a transition metal selected
from the group consisting of manganese, chromium, iron, cobalt,
nickel, and copper, and a polymerizable compound, and having a
solubility in a solvent which changes through a maximum and a
minimum with increase in energy imparted for polymerization.
2. A polymerizable film according to claim 1, wherein said film
passes through repeatedly a soluble state and an insoluble state in
the solvent with increase of energy imparted.
3. A polymerizable film according to claim 1, wherein said
polymerizable compound is formed into a film by a monomolecular
built-up method.
4. A polymerizable film according to claim 1, wherein said energy
for polymerization is at least one of heat, a near UV-ray, a
UV-ray, a far UV-ray, an electron beam, a soft X-ray and an
X-ray.
5. A polymerizable film according to claim 1, wherein said a
transition metal is manganese.
6. A polymerizable film according to claim 1, wherein the
polymerizable film containing a transition metal and a
polymerizable compound is formed into a film by use of a transition
metal salt of a polymerizable compound.
7. A polymerizable film according to claim 1, wherein the
polymerizable film containing a transition metal and a
polymerizable compound is formed by forming a film of a
polymerizable compound in a solution containing a transition metal,
and then incorporating the transition metal into the polymerizable
compound layer.
8. A polymerizable film according to claim 1, wherein the
polymerizable film containing a transition metal and a
polymerizable compound is obtained by forming a film of a
polymerizable compound and then dipping the formed film into a
solution containing a transition metal.
9. A polymerizable film according to claim 1, wherein the
polymerizable film containing a transition metal and a
polymerizable compound is constituted of a layer of a transition
metal and a layer of a polymerizable compound.
10. A polymerizable film according to claim 9, wherein said
transition metal layer is formed by vapor deposition or
electrolytic plating.
11. A polymerizable film according to claim 9, wherein said
polymerizable compound layer is formed by a monomolecular built-up
method.
12. A polymerizable film, comprising a transition metal selected
from the group consisting of manganese, chromium, iron, cobalt,
nickel, and copper, and a polymerizable compound represented by the
formula (I) shown below, and also having a solubility in a solvent
which changes through a maximum and a minimum with increase in
energy imparted for polymerization:
wherein R and R.sub.1 are hydrophobic sites, X is a hydrophilic
site, and n is 0 or 1.
13. A polymerizable film according to claim 12, wherein said film
passes repeatedly through a soluble state and an insoluble state in
the solvent with increase in energy imparted.
14. A polymerizable film according to claim 12, wherein said
polymerizable compound is formed into a film by a monomolecular
built-up method.
15. A polymerizable film according to claim 12, wherein said
polymerization energy is at least one of heat, a near UV-ray, a
UV-ray, a far UV-ray, an electron beam, a soft X-ray and an
X-ray.
16. A polymerizable film comprising a transition metal selected
from the group consisting of manganese, chromium, iron, cobalt,
nickel, and copper, and a polymerizable compound, and being capable
of giving rise to a first soluble state and a second soluble state
corresponding to the amount of polymerization energy imparted.
17. A polymerizable film according to claim 16, wherein the second
soluble state is greater in solubility in a solvent than the first
soluble state.
18. A polymerizable film according to claim 16, wherein said
polymerizable compound is a diacetylene compound represented by the
formula (I) shown below:
wherein R and R.sub.1 are hydrophobic sites, X is a hydrophilic
site, and n is 0 or 1.
19. A polymerizable film according to claim 16, wherein said
polymerizable compound is formed into a film by a monomolecular
built-up method.
20. A polymerizable film according to claim 16, wherein said
polymerization energy is at least one of heat, a near UV-ray, a
UV-ray, a far UV-ray, an electron beam, a soft X-ray and an
X-ray.
21. A polymerizable film having a layer containing a transition
metal selected from the group consisting of manganese, chromium,
iron, cobalt, nickel, and copper, and a polymerizable compound and
an intermediate layer, said layer containing the transition metal
and the polymerizable compound being a polymerizable film which
changes in solubility in a solvent through a maximum and a minimum
with increase of energy given for polymerization.
22. A polymerizable film according to claim 21, wherein said film
passes repeatedly through a soluble state and an insoluble state in
the solvent with increase in energy imparted.
23. A polymerizable film according to claim 21, wherein said
polymerizable compound is formed by a monomolecular built-up
method.
24. A polymerizable film according to claim 21, wherein said
polymerization energy is at least one of heat, a near UV-ray, a
UV-ray, a far UV-ray, an electron beam, a soft X-ray and an
X-ray.
25. A method of forming a pattern comprising preaparing a
polymerizable film comprising a transition metal and a
polymerizable compound having a solubility in a solvent which
changes repeatedly through a soluble state and an insoluble state
with increase in energy imparted and imparting variations in energy
to the film to form a soluble site and an insoluble site.
26. A pattern forming method according to claim 25, wherein said
polymerizable compound is a diacetylene compound represented by the
formula (I) shown below:
wherein R and R.sub.1 are hydrophobic sites, X is a hydrophilic
site, and n is 0 or 1.
27. A pattern forming method according to claim 25, wherein said
polymerizable compound is formed into a film by a monomolecular
built-up method.
28. A pattern forming method according to claim 25, wherein said
polymerization energy is at least one of heat, a near UV-ray, a
UV-ray, a far UV-ray, an electron beam, a soft X-ray and an
X-ray.
29. A method of forming a pattern comprising preparing a
polymerizable film comprising a transition metal and a
polymerizable compound having a solubility in a solvent which
changes repeatedly through a soluble state and an insoluble state
with increase in energy imparted and imparting variations in energy
to the film to form a first insoluble site and a second soluble
site.
30. A pattern forming method according to claim 29, wherein said
polymerizable compound is a diacetylene derivative compound
represented by the formula (I) shown below:
wherein R and R.sub.1 are hydrophobic sites, X is a hydrophilic
site, and n is 0 or 1.
31. A pattern forming method according to claim 29, wherein said
polymerizable compound is formed into a film by a monomolecular
built-up method.
32. A pattern forming method according to claim 29, wherein said
polymerization energy is at least one of heat, a near UV-ray, a
UV-ray, a far UV-ray, an electron beam, a soft X-ray and an
X-ray.
33. A method of forming a pattern comprising preparing a
polymerizable film comprising a transition metal and a
polymerizable compound having a solubility in a solvent which
changes repeatedly through a soluble state and an insoluble state
with increase in energy imparted and imparting variations in energy
to the film to form a second soluble site and a second insoluble
site.
34. A pattern forming method according to claim 33, wherein said
polymerizable compound is a diacetylene derivative compound
represented by the formula (I) shown below:
wherein R and R.sub.1 are hydrophobic sites, X is a hydrophilic
site, and n is 0 or 1.
35. A pattern forming method according to claim 33, wherein said
polymerizable compound is formed into a film by a monomolecular
built-up method.
36. A pattern forming method according to claim 33, wherein said
polymerization energy is at least one of heat, a near UV-ray, a
UV-ray, a far UV-ray, an electron beam, a soft X-ray and an
X-ray.
37. A pattern forming method, comprising a step of providing a
layer comprising a monomolecular film of a polymerizable compound
containing a transition metal or a built-up film thereof by way of
an intermediate layer on a substrate, and a step of polymerizing in
shape of a pattern by imparting energy to said layer.
38. A pattern forming method according to claim 37, wherein said
layer passes through a maximum and a minimum in its solubility with
increase in energy imparted.
39. A pattern forming method according to claim 37, wherein said
layer passes through a soluble state and an insoluble state with
increase in energy imparted.
40. A pattern forming method according to claim 37, wherein said
polymerizable compound is a diacetylene compound represented by the
formula (I) shown below:
wherein R and R.sub.1 are hydrophobic sites, X is a hydrophilic
site, and n is 0 or 1.
41. A pattern forming method according to claim 37, wherein said
polymerization energy is at least one of heat, a near UV-ray, a
UV-ray, a far UV-ray, an electron beam, a soft X-ray and an
X-ray.
42. A method of forming a pattern comprising providing on a
substrate an intermediate layer and a layer comprising a
monomolecular film of a polymerizable compound containing a
transition metal or a built-up film thereof, the compound having a
solubility in solvent which changes repeatedly through a soluble
state and an insoluble state with increase in energy imparted, and
imparting variations in energy to the layer to form a first
insoluble site and a second soluble site.
43. A pattern forming method according to claim 42, wherein said
polymerizable compound is a derivative compound represented by the
formula (I) shown below:
wherein R and R.sub.1 are hydrophobic sites, X is a hydrophilic
sites, and n is 0 or 1.
44. A pattern forming method according to claim 42, wherein said
polymerization energy is at least one of heat, a near a UV-ray, a
UV-ray, a far UV-ray, an electron beam, a soft X-ray and an
X-ray.
45. A method of forming a pattern comprising providing on a
substrate an intermediate layer and a layer comprising a
monomolecular film of a polymerizable compound containing a
transition metal or a built-up film thereof, the compound having a
solubility in a solvent which changes repeatedly through a soluble
state and an insoluble state with increase in variations in energy
imparted, and imparting energy to the layer to form a second
solubilized site and a second insolubilized site.
46. A pattern forming method according to claim 45, wherein said
polymerizable compound is a diacetylene compound represented by the
formula (I) shown below:
wherein R and R.sub.1 are hydrophobic sites, X is a hydrophilic
site, and n is 0 or 1.
47. A pattern forming method according to claim 45, wherein said
polymerization energy is at least one of heat, a near a UV-ray, a
UV-ray, a far UV-ray, an electron beam, a soft X-ray and an X-ray.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
This invention relates to a polymerizable film by use of a
polymerizable compound, particularly a polymerizable film suitable
for recording materials, and resist materials. Also, the present
invention relates to a pattern forming method by use of the
polymerizable film, particularly to a pattern forming method,
suitable for formation of a negative-type and positive-type
pattern. Also, the present invention relates to a pattern forming
method suitable for forming a negative-type and positive-type
pattern in a multi-layer resist system.
2. Prior Art
In the prior art, the resist for formation of a fine pattern in
production of a semiconductor device has been coated on a substrate
according to such a method as spin coating, bar coating, etc.
The coating method of the prior art, however, involves the
following drawbacks.
1. Pre-treatment, post-treatment such as prebaking, postbaking,
etc., are necessary.
2. Film quality, film thickness are nonuniform.
3. Adhesion to a substrate is weak.
4. Sensitivity and resolving power are limited. In contrast to
these methods, in recent years, studies have been made about resist
films having uniform film quality and thickness and also exhibiting
excellent adhesion to substrates by preparing the resist material
according to the monomolecular film built-up method
(Langmuir-Blodgett's method).
For example, there is the study in which the monomolecular film of
.omega.-tricosenic acid and its calcium salt is used as the
negative-type resist film (A. Barloe et al, Journal of Colloid and
Interface Science, vol. 62, No. 3).
However, this resist film had about the same extent of sensitivity
as that of the prior art (50 .mu.C/cm.sup.2), and was not
satisfactory.
On the other hand, when a film is formed on a silicon wafer or
aluminum vapor-deposited film by a monomolecular film built-up
method, the film will come off due to poor adhesion to the
substrate whereby built-up of the films could not easily conducted.
Further, the film also will come off during development after
polymerization. Thus it is not practically acceptable.
Electron beam drawing is generally poor in throughput, and
accordingly enhancement of the sensitivity is an important problem
for improvement in productivity and cost down.
SUMMARY OF THE INVENTION
Accordingly, the present invention has been accomplished to cancel
such drawbacks of the prior art.
An object of the present invention is to provide a novel
polymerizable film which can be used particularly for a resist, a
recording material of high sensitivity and high resolving
power.
Also, it is another object of the present invention to provide a
pattern forming method capable of forming particularly a pattern of
high sensitivity and high resolving power.
Still another object of the present invention is to provide a
pattern forming method capable of forming casily a positive type
and negative type pattern.
Further, still another object of the present invention is to
provide a pattern forming method capable of forming easily a
positive type and negative type pattern in a multi-layer resist
system.
According to an aspect of the present invention, there is provided
a polymerizable film, comprising a transition metal and a
polymerizable compound, and having a solubility in a solvent which
changes through a maximum and a minimum with an increase in energy
imparted for polymerization.
According to another aspect of the present invention, there is
provided a polymerizable film, comprising a transition metal and a
polymerizable compound represented by the formula (I) shown below,
and also having a solubility in a solvent which changes through a
maximum and a minimum with an increase in energy imparted for
polymerization:
wherein R and R.sub.1 are hydrophobic sites, X is a hydrophilic
site, and n is 0 or 1.
According to a still another aspect of the present invention, there
is provided a polymerizable film comprising a transition metal and
a polymerizable compound, and being capable of giving rise to a
first soluble state and a second soluble state correspondirg to the
amount of polymerization energy imparted.
According to a further aspect of the present invention, there is
provided a polymerizable film having a layer containing a
transition metal and a polymerizable compound and an intermediate
layer, said layer containing the transition metal and the
polymerizable compound being a polymerizable film which changes
repeatedly in solubility in a solvent through a maximum and a
minimum with increase of energy given for polymerization.
According to a still further aspect of the present invention, there
is provided a pattern forming method, comprising a step of
imparting energy to a polymerizable film comprising a transition
metal and a polymerizable compound, said film passing repeatedly
through a soluble state and an insoluble state in a solvent with an
increase in energy imparted, thereby forming a soluble site and an
insoluble site.
According to a still further aspect of the present invention, there
is provided a pattern forming method, comprising a step of
imparting an energy to a polymerizable film comprising a transition
metal and a polymerizable compound and passing repeatedly through a
soluble state and an insoluble state with increase in energy
imparted, thereby forming a first insoluble site and a second
soluble site.
According to a still further aspect of the present invention, there
is provided a pattern forming method, comprising a step of
imparting energy to a polymerizable film comprising a transition
metal and a polymerizable compound and passing through repeatedly a
soluble state and an insoluble state.
According to a still further aspect of the present invention, there
is provided a pattern forming method, comprising a step of
providing a layer comprising a monomolecular film of a
polymerizable compound containing a transition metal or a built-up
film thereof by way of an intermediate layer on a substrate, and a
step of polymerizing in shape of a pattern by imparting energy to
said layer.
According to a still further aspect of the present invention, there
is provided a pattern forming method, comprising a step of
providing a layer comprising a monomolecular film of a
polymerizable compound containing a transition metal or a built-up
film thereof and passing repeatedly through a soluble state and an
insoluble state with increase in energy imparted by way of an
intermediate layer provided on a substrate, and a step of imparting
an energy to said layer, thereby forming a first insoluble site and
a second soluble site.
According to a still further aspect of the present invention, there
is provided a pattern forming method, comprising a step of
providing on a substrate by way of an intermediate layer a layer
comprising a monomolecular film of a polymerizable compound
containing a transition metal or a built-up film thereof and
passing through a soluble state and an insoluble state with
increase in energy imparted, and a step of imparting an energy to
said layer, thereby forming a second solubilized site and a second
insolubilized site.
According to a still further aspect of the present invention, there
is provided a pattern forming method, comprising a step of
providing a layer having a polymerizable compound and a layer
having a transition metal by way of an intermediate layer on a
substrate, and a step of polymerizing the compound in a pattern by
imparting an energy to said polymerizable compound layer.
BRIEF DESCRIPTION OF THE DRAWINGS
FIGS. 1A and 1B are schematic illustrations showing the
polymerizable film of the present invention;
FIG. 2 is a graph showing the curve of normalized film thickness of
polymerizable film versus electron beam dose;
FIGS. 3A and 3B are a perspective view and a sectional view of a
device for preparation of the polymerizable film of the present
invention.
FIGS. 4A and 4B show schematically illustrations of the resist
layer formed on the substrate in that
DETAILED DESCRIPTION OF THE INVENTION
The polymerizable film of the present invention comprises primarily
a polymerizable compound and a transition metal.
The polymerizable compound used in the present invention is a
compound having at least one each of hydrophilic sites, hydrophobic
sites and polymerizable sites in the molecule.
As the polymerizable compound according to the present invention,
diacetylene compounds may be preferably employed.
The diacetylene compounds are represented by the following formula
(I).
wherein R and R.sub.1 denotes hydrophobic sites, X denotes a
hydrophilic site, and n means 0 or 1.
As the hydrophobic site R, there may be included, for example,
alkyl group, olefinic hydrocarbon group such as vinyl, vinylidene,
ethynyl, etc., phenyl, fused polycyclic phenyl group such as
naphthyl, anthranyl, etc., chain polycyclic phenyl group such as
biphenyl, terphenyl, etc., hydrogen atom or other non-polar groups,
and as R.sub.1, there may be employed an alkylene group, a
phenylene group, etc. Particularly, it is preferable that the total
number of carbon atoms in R and R.sub.1 should be preferably 10 to
30.
As the hydrophilic site X, preferable are a carboxylic group and
metal salts or amine salts thereof, a sulfonic acid group and metal
salts or amine salts thereof, a sulfamide group, an amide group, an
amino group, an imino group, a hydroxy group, a quaternary amino
group, an oxyamino group, a diazonium group, a guanidine group, a
hydrazine group, a phosphoric acid group, a silicic acid group, an
aluminic acid group, a nitrile group, a thioalcohol group, and
other polar groups, etc.
On the other hand, as the transition metal used in the present
invention, there may be included chromium, manganese, iron, cobalt,
nickel, copper, zinc, cadmium, etc., particularly preferably
manganese.
These transition metals may exist in either state of ion, complex
of salt in the film.
FIGS. 1A and 1B are schematic illustrations showing an example of
the polymerizable film of the present invention provided on a
substrate.
FIG. 1A represents a polymerizable film comprising a monomolecular
film, and FIG. 1B a polymerizable film comprising a monomolecular
built-up film.
A polymerizable film (a monomolecular film 6, a monomolecular
built-up film 8) containing a polymerizable compound 1 having a
hydrophilic site 2, a hydrophobic site 3 and a polymerizable site 4
and a transition metal 7 is formed on a substrate 5.
As a method for preparing a polymerizable film of the present
invention, there may be employed a spinner rotary coating method, a
roller coating method, a drawing-up coating method, a sputtering
method, a plasma polymerization method, a monomolecular built-up
method, etc. When high density and high orderliness of the film
prepared are taken into consideration, particularly the
monomolecular built-up method is preferred.
As the method for forming a monomolecular film or a built-up film
thereof having such high orderliness and high orientation of
molecules, for example, there may be employed the
Langmuir-Blodgett's technique developed by I. Langmuir et al
(hereinafter called LB technique).
The LB method is a method for preparing monomolecular films or
built-up films thereof by employing a molecule having a hydrophilic
portion and a hydrophobic portion in the molecule in which
hydrophilicity and hydrophobicity are well balanced, and utilizing
the orientation of the molecule on a water surface with a
hydrophilic group directing downward.
The monomolecular layer formed on the water surface has the
characteristic of a two-dimensional system. When the molecules are
dispersed sparsely, the equation of a two-dimensional ideal gas is
valid between the area A for one molecule and the surface pressure
.pi., thus becoming "a gaseous film":
wherein K is the Boltzman's constant and T is an absolute
temperature.
When A is made considerably small, the interaction between the
molecules becomes larger, whereby the film turns "condensed film
(or solid film)" of a two-dimensional solid. The condensed film can
be transferred one by one onto the surface of a carrier made of
various materials in various shapes such as a glass substrate.
Referring now to FIG. 3, the specific method for preparing a
monomolecular film or its built-up film of a diacetylene compound
constituting the polymerizable film of the present invention
according to this method is described below.
First, a desired diacetylene compound 1 is dissolved in a volatile
solvent such as benzene, chloroform, etc.
The solution of this diacetylene compound 1 is spread over the
aqueous phase 10 in a water tank 9 to form a film.
Next, the spreading area is restricted by providing a partitioning
plate (or buoy) 11 so that the spread layer may not expand by free
diffusion over the aqueous phase 10, thereby controlling the
gathered state of the film substance to obtain a surface pressure
.pi. which is in proportion to the gathered state.
By moving this partitioning plate 11, the spreading area can be
reduced to control the gathered state of the film substance, to
increase the surface pressure gradually to reach a surface pressure
.pi. which is suitable for a production of a built-up film.
By moving vertically a clean carrier (or a substrate) 12 gently
while maintaining this surface pressure, a monomolecular film of
the diacetylene compound is transferred onto the carrier
(substrate) 12.
The monomolecular film of the diacetylene compound is produced as
described above, and by repeating the above operation, a built-up
film of monomolecular film of the diacetylene compound made of
desired built-up number of films can be formed.
For transfer of the diacetylene monomolecular film onto the carrier
12, other than the vertical dipping method as described above,
there are methods according to the horizontal lifting method, the
rotatory cylinder method, etc.
The horizontal lifting method is a method for transferring the film
by bringing the carrier (substrate) 12 into contact horizontally
with the water surface, while the rotatory cylindrical method is a
method for transferring the film onto the carrier surface by
rotating a cylindrical carrier on the water surface.
In the vertical dipping method as described above, when a carrier
12 with hydrophilic surface is withdrawn from water in the
direction transversing the water surface, a diacetylene
monomolecular film is formed on the carrier with the hydrophilic
site 2 of the diacetylene compound directed toward the carrier
side.
When the carrier is moved vertically, the diacetylene monomolecular
film is laminated by one layer in each step.
In this case, since the direction of the film forming molecule is
reversed in the withdrawing step and the dipping step, the Y type
film in which the hydrophilic site 2 and the hydrophilic site 2 of
the diacetylene derivative are opposed to each other in adjacent
layers is formed according to this method.
In contrast, according to the horizontal lifting method, the
diacetylene monomolecular film with the hydrophobic site 3 of the
diacetylene compound 1 directed toward the carrier side is formed
on the carrier.
According to this method, even when the film is built-up, there is
no alternation in the direction of the film forming molecule, but
the X-type in which the hydrophobic site 3 is directed toward the
carrier side in all the layers is formed. On the contrary, the
built-up film in which the hydrophilic site 2 is directed toward
the carrier side in all the layers is called the Z-type film.
The method for transferring the monomolecular layer onto a carrier
is not limited to these, but it is also possible to extrude a
carrier into an aqueous phase from a carrier roll when a large area
of a carrier is desired. The direction of the hydrophilic site and
the hydrophobic site as described above is a general principle, and
it can be changed by the surface treatment of the carrier, etc.
In the present invention, as the method for incorporating the
transition metal in a monomolecular film or a built-up film of the
diacetylene derivative compound, there may be included:
1. a method in which a film is formed by use of a transition metal
salt of a diacetylene compound;
2. a method in which a solution containing a transition metal is
dissolved in the aqueous phase 10, and the transition metal is
incorporated into the film in the step of building up monomolecular
films;
3. the method in which after preparation of a monomolecular
built-up film, said built-up film is dipped in a solution
containing a transition metal, etc., and any method can be used to
accomplish the objects of the present invention.
In the present invention, it is also possible to attach a
transition metal or a transition metal compound onto a substrate
according to the method such as vapor deposition or electrolytic
plating, and form a monomolecular built-up film of a diacetylene
derivative compound thereon.
As the substrate or carrier for forming a polymerizable film, there
may be employed various solid materials such as glass, plastic,
paper, metal, etc., but when utilizing the polymerizable film of
the present invention, for example, a resist film, silicon wafer or
silicon wafer having aluminum vapor deposited film or chromium
vapor deposited film on the surface, etc., may be preferably used
as the substrate.
The polymerizable film of the present invention may be a
polymerizable thin film having a film thickness of generally some
10 .ANG. to about some .mu.m, preferably 100 .ANG. to 5000 .ANG..
The preferable thickness depends on the uses of the film.
In the present invention, the polymerizable film may be provided by
way of an intermediate layer on the substrate and pattern formation
may be effected by imparting an energy to said layer.
FIGS. 4A and 4B show schematically illustrations of the resist
layer formed on the substrate in that embodiment. The layers 6, 8
provided by way of the intermediate layer 20 comprise primarily a
polymerizable compound 1 and a transition metal 7.
The intermediate layer employed in the present invention may be one
used in a conventional multi-layer resist system, including
one-layr constitution comprising a photoresist layer or two-layer
constitution comprising a photoresist layer and a layer of an
inorganic material.
As the material constituting the photoresist layer, any of
compounds conventionally used as a positive type, and a negative
type of resist material known in the art can be preferably
used.
For example, as the positive type of resist material, there may be
included polymethacrylates such as polymethyl methacrylate,
polyethyl methacrylate, etc., polymers and copolymers of methyl
.alpha.-chloroacrylate, vinylidene chloride copolymers, polymethyl
.alpha.-trifluoromethyl acrylate, polymethacrylamide, poly-t-butyl
methacrylate, etc. On the other hand, as the negative type of
resist material, there may be included polyglycidyl methacrylate,
glycidyl methacrylate-ethyl actylate, MMA-ethylacrylate-glycydyl
methacrylate ternary copolymer of which a part of glycidyl groups
are reacted with methacrylic acid, etc.
As the material constituting the inorganic material layer, Si, Ti,
siloxane, etc., may be employed.
In the present invention, as the method for forming an intermediate
layer on the substrate 5, there may be employed a spinner rotatory
coating method, a roller coating method, a drawing-up coating
method, a sputtering method, a plasma polymerization method, a
monomolecular built-up method, etc.
The intermediate layer of the present invention preferably
comprises a photoresist layer having a thickness of about 1 to 3
.mu.m, and the inorganic layer, having a thickness of about 0.1 to
0.5 .mu.m.
The dependency of the solubility of the polymerizable film in a
solvent on the dose of energy for polymerization to the film is
illustrated in FIG. 2. The film thickness therein is a normalized
value after the dose of the energy and the development (namely,
thickness of the remaining film).
FIG. 2 illustrates the change of the solubility of the
polymerizable film containing manganese and a diacetylene compound
in ethanol as a solvent passing through a maximum and a minimum
with increasing exposure to an electron beam.
The solubility is high before exposure to an electron beam (namely
a first soluble state). The solubility changes with increasing
exposure through an insoluble state (a first insoluble state), a
soluble state (a second soluble state), and an insoluble state (a
second insoluble state). The solubility is higher in the second
soluble state than in the first soluble state.
The pattern-forming method of the present invention is based on the
characteristics of the above polymerizable film, and embodiment as
shown below are included:
1. the embodiment in which a negative type pattern is formed by
utilizing the difference in solubility between the
electron-beam-unexposed portion (a first soluble site) and the
first insoluble site;
2. the embodiment in which a positive type pattern is formed by
utilizing the difference in solubility between the first insoluble
site and the second soluble site;
3. the embodiment in which a negative type pattern is formed by
utilizing the difference in solubility between the second soluble
site and the second insoluble site.
Although any of these embodiments may be preferably utilizable, the
second and the third embodiments are preferred in which the
difference in solubility in the solvent is particularly great.
The polymerization energy to be used in the present invention may
include heat, a near UV-ray, a UV-ray, a far UV-ray, an electron
beam, a soft X-ray, an X-ray and other electromagnetic waves, and
at least one of them may be used.
The solvent to be used for development may include water or organic
solvent such as methanol, ethanol, acetone, etc.
In the present invention, developing treatment is essential in
pattern formation, but no developing treatment is necessarily
required in such a case where the subbing layer is subjected to
etching subsequent to the pattern formation. The soluble site
formed by imparting of energy has extremely low resistance to
etching, the film can be easily peeled off during etching without
performing development.
For etching of the subbing layer, carbon tetrafluoride plasma,
oxygen plasma, etc., known in the art may be employed.
In order to describe the present invention in more detail, Examples
are set forth below.
EXAMPLE 1-2
As the aqueous phase 10, a solution was prepared by dissolving
manganese chloride tetrahydrate in pure water at a concentration of
1.times.10.sup.-4 M and further potassium hydrogen carbonate to
5.times.10.sup.-5 M, followed by adjustment of pH 6.4. The water
temperature was controlled to be maintained at 20.degree. C.
As the diacetylene compound, 10, 20-pentacosadiynoic acid
represented by the following formula:
was dissolved at a concentration of 1.times.10.sup.-3 M in
chloroform, and 200 .mu.l of the solution was spread over the
aqueous phase 10.
After evaporation of the solvent chloroform, the partitioning plate
11 was moved to enhance the surface pressure to 20 mN/m.
As the substrate 12, an n.sup.+ type silicon wafer doped with
antimony (resistance value 0.010-0.011 .OMEGA.cm.sup.-1) from which
oxide film on the surface had been removed with hydrofluoric acid
was employed.
This substrate was moved gently upward and downward at a speed of
10 mm/min in the direction transversing the water surface to form a
monomolecular built-up film of 30 layers.
When the monomolecular film on the aqueous phase is transferred
onto the substrate, the surface pressure of the monomolecular film
on the aqueous phase is lowered. Accordingly, in order to maintain
the surface pressure at a constant level, the surface pressure is
monitored by a surface pressure meter 16 connected through the
surface pressure paper 14 and the suspending yarn 15, and the
partitioning plate 11 is moved through the control circuit system
17.
As the result of measurement of the monomolecular built-up film
formed according to the above method by X-ray scattering and atomic
absorption analysis, the molecular built-up film was found to have
a layered structure with a thickness of one layer of 31 .ANG., and
it was confirmed that manganese was incorporated as the carboxylic
acid salt of the diacetylene compound.
The polymerizable film thus formed on the substrate was dried in
air for 24 hours.
The polymerizable film formed on the substrate as described above
was placed in an electron beam lithography system ELS-3300 produced
by Elionix Co., and drawing was conducted by use of a pattern
generating device under the conditions of an accelerating voltage
of 20 KV, current values of 1.times.10.sup.-10 A and
1.times.10.sup.-11 A. The magnification at this time was 50-fold,
with the stationary spot diameter being 0.1 .mu.m in diameter and
the delivery pitch being 0.1 .mu.m.
After drawing by setting the exposure time at 0.5 .mu.sec/spot-256
.mu.sec/spot, development was effected in ethanol and the film
thickness after development was measured by ellipsometry by use of
633 nm helium-neon laser (produced by Gaertner Scientific Corp.) to
prepare a sensitivity curve. The results are shown in Table 2.
As shown in FIG. 2, D.sub.0.5 (the exposure dose for 50% remaining
thickness) of the film after development became 0.5 .mu.C/cm.sup.2
or less, thus showing higher sensitivity by far than the resist
film (50 .mu.C/cm.sup.2) by use of the monomolecular film of
.omega.-tricosenic acid of the prior art.
Next, after drawing lines with a line thickness and interlinear
space of 1 .mu.m-0.1 .mu.m on the polymerizable film at electron
beam doses of 0, 0.4, 8, and 200 .mu.C/cm.sup.2, respectively,
development processing in ethanol was effected for 5 minutes, and
the normalized value of the film thickness after development was
compared.
The remaining film was less in amount at the exposed portion with a
dose of 8 .mu.C/cm.sup.2 than at the unexposed portion with a dose
of 0 .mu.C/cm.sup.2, and the contrast relative to the exposed
portions with doses of 0.4 .mu.C/cm.sup.2 and 200 .mu.C/cm.sup.2
was higher. Moreover, a pattern with a resolving power of 0.2 .mu.m
could be also formed.
EXAMPLE 1-2
As the aqueous phase 10, pure water was employed and potassium
hydrogen carbonate was dissolved to 5.times.10.sup.5 M.
As the diacetylene compound 1, manganese salt of 2,4-tricosadiynoic
acid represented by the following formula:
was dissolved at a concentration of 1.times.10.sup.-3 M in
chloroform, and 200 .mu.l of the solution was spread over the
aqueous phase 10, and the partitioning plate 11 was moved to
enhance the surface pressure to 30 mN/m.
As the substrate 12, a silicon wafer having aluminum vapor
deposited thereon was used.
On this substrate, film formation was effected similarly as in
Example 1.
The polymerizable film was subjected to exposure by use of PLA520FA
produced by Canon. At a wavelength of 290 nm and a luminance of 13
mW/cm.sup.2, drawing was conducted by varying the exposure time
from 5 seconds to 40 seconds.
After development with ethanol, the film thickness after
development was measured to determine sensitivity, and a curve
similar to FIG. 2 was obtained. At D.sub.0.5, the exposure time
became about 5 seconds, and thus it was confirmed that the film
obtained was a resist film having a sensitivity which was higher by
far than the resist film of the prior art.
EXAMPLE 1-3
As the aqueous phase 10, an aqueous 1.times.10.sup.-4 M cadmium
chloride solution was employed, and further sodium hydrogen
carbonate was dissolved to 5.times.10.sup.-5 M.
As the diacetylene derivative compound, 22,24-pentacosadiynoic acid
represented by the following formula:
was dissolved at a concentration of 1.times.10.sup.-3 M in
chloroform, and the partitioning plate was moved to enhance the
surface pressure to 40 mN/m.
As the substrate 12, a silicon wafer of which surface was thermally
oxidized to a SiO.sub.2 film of 1000 .ANG. A was employed.
After film formation according to the same method as described
above, the film was dipped in an aqueous manganese solution and
left to stand for 1 hour.
As the result of measurement of the monomolecular built-up film by
atomic absorption analysis, it was confirmed that cadmium in the
monomolecular built-up film was replaced with manganese.
This polymerizable film was polymerized with UV-ray of 254 nm, and
was found that the polymerization rate and the polymerization yield
were better by far than other metals.
EXAMPLE 2-1
The same polymerizable film was formed on the substrate as in
Example 1-2, and was polymerized with UV-ray of 254 nm. As the
result, the solid phase polymerization occurred to form a first
insoluble state.
Next, electron beam was irradiated following a pattern to the total
dose of 8 .mu.C/cm.sup.2, followed by development with ethanol for
5 minutes.
As the result, a positive type pattern of high contrast and high
resolving power was formed.
EXAMPLE 2-2
The same polymerizable film was formed on the substrate as in
Example 1-3, and was placed in the same electron beam drawing
device as in Example 1-1, and subjected to patterning by use of two
electron beam doses of 8 .mu.C/cm.sup.2 and 100 .mu.C/cm.sup.2,
followed by development with ethanol.
As the result, the site at the dose of 8 .mu.C/cm.sup.2 was
dissolved, while the site at the dose of 100 .mu.C/cm.sup.2 became
insoluble to leave the film.
When this film was subjected to etching in a plasma of carbon
tetrafluoride, SiO.sub.2 coating was etched at the site of the dose
of 8 .mu.C/cm.sup.2 to have the subbing silicon exposed, while 1000
.ANG. of the SiO.sub.2 coating remained at the site of the dose of
100 .mu.C/cm.sup.2. Thus, excellent etching resistance was
confirmed.
EXAMPLE 3-1
As the substrate 12, one subjected to the following treatment was
employed.
The oxide film was removed from the surface of the n.sup.+ type
silicon wafer doped with antimony (resistance value 0.010-0.011
.OMEGA.cm.sup.31 1) with hydrofluoric acid, and PIG (a polyimide
type resist) was applied to a thickness of 1 .mu.m thereon by use
of a spinner, etc., followed by curing at 250.degree. C. On this
film was further applied siloxane to a thickness of 0.1 .mu.m.
The substrate having the above resist on the surface was moved
gently vertically at a speed of 10 mm/min in the direction
transversing the water surface to form a monomolecular built-up
film of 30 layers having the same components as in Example 1-1.
Next, after drawing lines with a line thickness and interlinear
space of 1 .mu.m-0.1 .mu.m on the layer having this monomolecular
built-up film by use of two electron beam doses of 0.4
.mu.C/cm.sup.2 and 8 .mu.C/cm.sup.2, development was effected with
ethanol for 5 minutes.
After thus forming a pattern comprising a monomolecular built-up
film, the siloxane film was etched by use of a plasma of carbon
tetrafluoride, ard subsequently PIG was etched by use of a plasma
of oxygen.
As the result, a pattern of extremely high contrast and yet with a
resolving power of 0.2 .mu.m could be formed.
EXAMPLE 3-2
As the substrate 12, a silicon wafer having aluminum vapor
deposited to 1000 .ANG. thereon was coated with AZ1350J to a
thickness of 2 .mu.m and, after post-baking at 20.degree. C.,
further titanium was vapor deposited to a thickness of 0.3 .mu.m
thereon.
By use of the resist coated substrate, a monomolecular built-up
film having the same components as in Example 1-2 was formed.
When this monomolecular built-up film was polymerized with a UV-ray
of 254 nm, the solid phase polymerization occurred to give a first
insoluble state.
Next, electron beam was projected following a pattern to the total
dose of 8 .mu.C/cm.sup.2, followed by development with ethanol for
5 minutes.
After having thus formed a pattern comprising a monomolecular
built-up film, the titanium film was etched by use of a plasma of
carbon tetrafluoride, and subsequently AZ1350J was etched by use of
a plasma of oxygen.
As the result, a positive type pattern of high contrast and high
resolving power was formed.
EXAMPLE 3-3
As the substrate 12, on the silicon wafer of which surface was
thermally oxidized to form SiO.sub.2 film of 1000 .ANG. thereon, 2
.mu.m of polymethyl methacrylate (PMMA) was applied in the same
manner as in Example 1-3 to a thickness of 2 .mu.m, followed
further by coating of siloxane to a thickness of 0.1 .mu.m
thereon.
After film formation according to the same method as in Example
1-3, the film was dipped in an aqueous manganese solution and left
to stand for 1 hour.
The resist coated substrate having the layer containing the
monomolecular built-up film was placed in the same electron beam
lithography system as in Example 1-1, and patterning was effected
by use of two electron beam doses of 8 .mu.C/cm.sup.2 and 100
C/cm.sup.2, followed by development with ethanol.
As the result, the site of the dose 8 .mu.C/cm.sup.2 was dissolved,
and the site of the dose 100 .mu.C/cm.sup.2 made insoluble to leave
the film.
When this was subjected to etching in a plasma of carbon
tetrafluoride and then in a plasma of oxygen, the SiO.sub.2 coating
was etched at the site of the dose 8 .mu.C/cm.sup.2 to have the
subbing silicon exposed, while the SiO.sub.2 coating of 1000 .ANG.
remained at the site of the dose 100 .mu.C/cm.sup.2. Thus excellent
etching resistance was confirmed.
EXAMPLE 4-1
A polymerizable film was formed in the same manner as in Example
1-1, and the polymerizable film was exposed to an X-ray by passing
the X-ray generated under the conditions of a voltage of 20 KV and
a current of 48 mA by use of Rh bulb (wavelength 4.6 .ANG.)
produced by Machlett Co. through a window of Be in a vacuum of
6.times.10.sup.-2 torr or higher for 1 minute (20 mJ/cm.sup.2) to
draw a line with a line thickness and space of 0.3 .mu.m, followed
by development with ethanol for 5 minutes.
As the result, a pattern of extremely high contrast and yet with a
resolving power of 0.3 .mu.m could be formed.
EXAMPLE 4-2
A polymerizable film was formed in the same manner as in Example
1-2. This polymerizable film was exposed to X-ray under the same
conditions as in Example 4-1 (the exposure time was 1 minute) to
effect polymerization. As the result, the solid phase
polymerization occurred to give a first insoluble state. Next, it
was exposed to an X-ray under the same conditions as in Example 4-1
(but the exposure time was 30 sec.) following a pattern, followed
by development with ethanol for 5 minutes.
As the result, a positive type pattern of high contrast and high
resolution was formed.
The polymerizable film of the present invention has the following
effects.
1. Adhesion to a substrate is excellent.
2. Film quality is uniform and dense.
3. When used as the resist material, a pattern of high resolving
power and high contrast can be formed.
Also, as compared with the resist material of the prior art,
sensitivity is higher (with D.sub.0.5 being about 0.1
.mu.C/cm.sup.2 or lower), and the throughput of the electron beam
drawing is increased to improve productivity.
4. When used as recording material, rewriting, addition of writing
are possible, and recording of high density, high sensitivity and
high resolving power is possible.
Consequently, beam current can be reduced to lower temperature
elevation.
5. Not only as the resist material, but it is also useful as
printing plates for printing, thin film insulators, semiconductors,
conductors.
The pattern forming method of the present invention has the
following effects.
6. Due to excellent adhesion to substrate, etching resistance is
excellent.
7. Due to uniform and dense film quality, a pattern of high
sensitivity, high resolving power and high contrast can be
formed.
8. Since an UV-ray and an electron beam can be used in combination
for pattern formation, the drawing time can be shortened to a great
extent.
9. A positive type or negative type pattern can be formed easily as
desired.
10. By use of a layer comprising a monomolecular film or a
monomolecular built-up film as the upper layer of a multi-layer
resist system, pinholes of the upper layer and adhesiveness between
layers which have been the problems in the multi-layer resist
system of the prior art can be overcome.
11. Since the layer having a monomolecular film or a monomolecular
built-up film of a polymerizable compound containing a transition
metal is laminated through an intermediate layer on the substrate,
short circuit caused by the metal will never occur.
* * * * *